The Olfactory Response of Adults to Volatiles and Compare of Toxicity of Different Insecticides to the Adults and Larvae of Bradysia odoriphaga

The olfactory response of the adults of Bradysia odoriphaga to 4 kinds of volatile was mensurated by using "Y" form glass tube apparatus, and the LC50 values of insecticides to the adults and 4th instar larvae of the pest were tested as well. The results demonstrated that the fresh chives Alliun tuberosum, garlicin, alcohol extract of garlic, and calcium polysulfide were all rather good temptations to the adults. Under the condition of the most suitable concentration of these volatiles, the selective coefficient of the 4 materials was 0.77, 0.78, 0.46 and 0.36 respectively. Among 8 kinds of insecticides, alpha-cypermethrin possessed the highest knockdown toxicity to the adults, and the KT50 was 7.9382 min. After then, KT50 of carbosulfan and phoxim was 14.285 min and 20.465 min respectively. The knockdown toxicity of chlorfluazuron was the lowest, and the KT50 was only 94.210 min. Among 6 kinds of insecticides, the toxicity of chlorpyrifos to the 4th instar larvae was the highest, then were the toxicity of chlorfluazuron and phoxim, and that of diazinon was the lowest. According to the habit of both adults and larvae as well as the work characteristics of the different insecticides, the control method combining aboveground with underground treatments was put forward. The possibility of directional controlling the adults was explored based on the attractive effect of exogenous volatiles to the adults.